In U.S. Pat. No. 4,302,941 there is described a combustor liner construction for a gas turbine engine. As disclosed there, a cylindrical combustor shell is protected with a plurality of combustor liner segments. Posts on the liner segments pass through the wall of the shell for support in a manner to permit floating of these segments.
U.S. Pat. No. 4,512,159 shows a clip attachment for securing these posts. The post has a reduced thickness portion remote from its outer end and the clip has a slot which engages this reduced thickness portion. The leg of the clip which is secured to the post is bent sinusoidally to apply opposing forces to the shell and to the post, thereby maintaining a flexible loading against the post.
The other leg of the U-shaped clip is bent inwardly toward the post. It has a hole therein which fits over the post with one edge of the hole engaged against the post. This prevents the clip from dislodging backwardly.
Not only do these segments expand relative to the shell requiring some movement in each post support area, but considerable vibration exists in the engine. When insufficient preload exists or is lost during operation, vibration occurs between the post and the clip. This causes rubbing and fretting between the portion of the clip engaging the head of the post and the clip in that area. When this wears through the retainer fails entirely and falls off leaving a completely unsupported post.